Lindsay Lohan -- Probation Dept. Wants Jail

9/22/2010 8:50 AM PDT

Lindsay Lohan -- Probation Department Wants Jail Time

The L.A. County Probation Dept. will recommend that Judge Elden Fox throw Lindsay Lohan in jail for failing two drug tests ... TMZ has learned.

We broke the story ... Lindsay tested positive for both cocaine and amphetamines.

And this is interesting ... our sources say the D.A. will not make a recommendation when Lindsay appears in court Friday AM.

Lindsay could get 30 days for each failed test.